bomberjeff
rep me dawg
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- Jun 30, 2026
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- What is MK-667?
- How does it work?
- Pros & Cons
- Who should take MK-667
- What to do if you choose to take it
- My Experience
- FAQs
Disclaimer: MK-667 is an experimental compound that has not been approved more medical use. Since long-term health effects have not been studied, caution is advised.
MK-667 (also known as Ibutamoren and LUM-201) is a potent chemical compound that can help people grow, sleep better, gain muscle mass, and a host of other benefits. It mimics the chemical structure of Ghrelin, the hormone that causes hunger. This causes an increase in perceived hunger by the user, which can help people who have trouble putting on mass to gain weight. The following effects have been observed during supplementation:
Positive effects:
Positive effects:
- Increases lean muscle mass (https://pubmed.ncbi.nlm.nih.gov/8954023/)
- Increases bone density (https://academic.oup.com/jbmr/artic...ctedFrom=fulltext&login=false#google_vignette)
- Increases growth (in those with open growth plates) by increasing growth hormone secretion (https://pmc.ncbi.nlm.nih.gov/articles/PMC9227666/#T1F2)
- Currently being studied for its effects on heigh velocity (the speed at which children grow) (https://pmc.ncbi.nlm.nih.gov/articles/PMC9227666/#T1F2)
- Increase in growth hormone results in better recovery and reduced risk of injury
- Increases collogen production, resulting in fuller and more healthy-looking skin (https://academic.oup.com/edrv/artic...?redirectedFrom=fulltext&login=false#51300106)
- Increase in sleep quality and duration (https://pubmed.ncbi.nlm.nih.gov/9349662/)
- Increases cortisol, the stress hormone that causes bloating (https://pmc.ncbi.nlm.nih.gov/articles/PMC2757071/)
- Can cause insulin resistance, which can lead to diabetes if not carefully managed (https://teletest.ca/blog/side-effects-and-risks-of-mk-677/)
- May slightly decrease testosterone (https://pmc.ncbi.nlm.nih.gov/articles/PMC2757071/)
- Increases aggressiveness of cancer
- May be mildly toxic to the liver (https://examine.com/other/ibutamoren/)
- Increased feeling of tiredness (can be inconvenient and lead to worse results in the gym due to less intense training)
- Increased feelings of hunger (can cause overeating and lead to unintended fat gain)
MK-667 affects the IGF-1 (Insulin like Growth Factor - 1) and the GH (Growth Hormone) axis in your body. It does this by activating certain proteins via calcium channels, which eventually leads to increased secretion of GH. GH both increases cell growth, and stimulates the liver to produce IGF-1, which itself also increases cell growth (see image)
Logically, this would both increase your fat mass and your fat free mass. But, MK-677 also reduces nitrogen wasting, which is the process when your body breaks down muscle tissue into amino acids for energy. This causes MK-667 to increase your muscle mass more than fat mass. Due to a dose of just 25mg/day increasing your IGF-1 levels by up to 97%, it also causes insulin sensitivity. This is because the IGF-1 molecule also bonds to your body's insulin receptor when it is at high levels in the blood, due to it being chemically similar to insulin. This causes your body to become less sensitive to insulin since it's insulin receptors are being flooded with input, just like it would be to any other drug. Thus, when taken for a long period of time MK-667 can lead to diabetes.
Pros:
- Increased overall growth (including height and facial bones, if genetics permit)
- Increased muscle gain
- Relatively inexpensive
- Does not require injection due to it being orally bioavailable
- Legal
- Does not significantly decrease natural hormone levels (due to it making your body secrete more GH instead of replacing natural levels)
- Has other anti-aging effects (e.g decreasing bone age and increasing skin quality)
- Insulin sensitivity
- Addictive (explained more in section 6)
- Not particularly well studied compared to other supplements
- Not regulated, so if you buy it you may receive the incorrect dose, nothing at all, or a different compound altogether
- Makes you appear more bloated
- Can lead to fat gain
- Probably causes liver damage over time
- People under 18 (can take advantage of full growth-enhancing effects)
- People who have trouble sleeping
- People who are skinny and have trouble gaining mass
- People who would like the anti aging benefits
- People who are diabetic, prediabetic, or diabetes is common in their family (if you have not been told so, you can assume you are not)
- People who are already a high body fat (will just get fatter)
- People who have liver disease or are taking a medication that interferes with liver function (e.g Accutane)
- People who have previously been addicted to drugs (it's addictive)
- Professional Athletes and soldiers (banned substance)
Make sure you are taking a safe, yet effective dose. I recommend taking 10-15 mg per day to start, then increase to something like 25mg once you are familiar with how you respond to it. It is important to choose the correct time of day to take it; If you want to become more hungry to bulk up, than take it in the morning, whereas if you just want the other effects and you want to minimize fat gain, take it in the evening. But, taking it in the morning will make you more tired throughout the day.
Monitor your blood glucose, if necessary.
This will help you know if you are experiencing insulin resistance. This will require a blood glucose monitor and you need to draw blood to measure it. I would recommend doing this if you are taking it for more than 4 months straight, or if you are predisposed to diabetes because the effects will compound and you need to make sure you are not going to experience an issue. To do this simply follow the instruction on the glucose monitor, and look up the recommended range for your age and the time of your most recent meal. If you are in the recommended range, you are fine to continue.
Monitor your blood glucose, if necessary.
This will help you know if you are experiencing insulin resistance. This will require a blood glucose monitor and you need to draw blood to measure it. I would recommend doing this if you are taking it for more than 4 months straight, or if you are predisposed to diabetes because the effects will compound and you need to make sure you are not going to experience an issue. To do this simply follow the instruction on the glucose monitor, and look up the recommended range for your age and the time of your most recent meal. If you are in the recommended range, you are fine to continue.
Q: Is MK-677 Legal?
A: Everywhere except Australia, MK-677 is legal to buy and consume, although it relies on a legal loophole due to its classification as a "research chemical".
Q: Where should I buy MK-677?
A: Although I believe promotion of certain websites is not allowed on this forum, just doing some research on google for 5 minutes can show you where to go.
Q: How expensive is MK-677?
A: Around $80 US for a 50 day supply.
A: Everywhere except Australia, MK-677 is legal to buy and consume, although it relies on a legal loophole due to its classification as a "research chemical".
Q: Where should I buy MK-677?
A: Although I believe promotion of certain websites is not allowed on this forum, just doing some research on google for 5 minutes can show you where to go.
Q: How expensive is MK-677?
A: Around $80 US for a 50 day supply.
